1. Field of the Invention
This invention relates to the art of sensing and control techniques for laundry apparatus, and is particularly concerned with methods and apparatus for sensing the moisture content of a clothes load within a dryer and controlling the operation of the clothes dryer as a function thereof.
2. Description of the Prior Art
U.S. Pat. No. 3,702,030 discloses a high voltage sensor circuit for an integrated circuit control that produces repetitive pulses when the clothes load is dryer than a given dryness level for resetting a second counter to prevent the second counter from resetting a first counter. The first counter, upon reaching a predetermined count, ends the sense portion of the drying cycle. Similar circuits are utilized in U.S. Pat. Nos. 3,762,064 and 3,769,716.
U.S. Pat. No. 3,621,293 discloses the use of a field effect transistor for sensing voltage buildup on a capacitor in a drying control.
U.S. Pat. No. 3,221,417 discloses a moisture sensor control circuit. Rotating cams and a timer motor along with a motor driven rotor switch arm are utilized which successively closes circuits causing a capacitor to be charged. The capacitor is connected to a pair of spaced electrodes and then to a relay. If the charge on the capacitor does not discharge through the electrodes, it will remain to power the relay for terminating the drying operation.